Welcome to Collateral Damage, the new home for BP's injury beat. As you’ve probably gathered from the byline above, my name is Corey Dawkins. I’ve trained in sports medicine and have served as an Athletic Trainer at Division I and Division III schools (Division II has been holding out on me), as well as one of the leading sports medicine clinics in the nation. In this column, which I will be co-authoring with BP stalwart Marc Normandin, we hope not only to help you keep up to date with the latest injury news, but also to help you understand the nature of each ailment, what each rehab process is like, and how debilitating each injury may be to the performance of the player in question.

In the coming weeks, Marc and I will also be presenting revamped Team Injury Projections. These will focus more on team analysis—i.e., a review of 2010’s injuries and the impact of potential injuries on the current squad—and we will complement them with player listings separated by position. We will start rolling these out soon and will complete the series before Opening Day. With that out of the way, it’s time to get to the injuries.

Justin Morneau (Concussion)

Justin Morneau has been dealing with the effects of post-concussion syndrome since July 2010. He was recently cleared to participate in all spring training drills, which is one of the few high points on what has been a long journey for Morneau—one that was concerning at times given the duration of the symptoms. The effects of concussions and sub-concussive events have been gaining ground in the media over the last several years. This trend peaked during football season after a rash of concussions suffered by current players followed complaints from retired players regarding head injuries and associated long-lasting damage. Baseball’s concussion issues haven’t garnered the same level of media attention, but the sport still carries a risk of concussion with every play.

Morneau found this out the hard way last July 7, after taking a knee to the head while sliding into second base. There is no telling what causes the length or severity of the symptoms, but anecdotal evidence suggests that the forces that produce a rotation of the head along with movement in the two planes (imagine whiplash, but with a rotational component) increase the possibility of severe symptoms. That's exactly what happened with Morneau: his head was bent forward, towards his left shoulder, and it rotated to the left as he was hit by John McDonald’s knee.

The brain is like any other body part in that when it gets injured, it needs rest and time to recover. In the case of something as simple as a mild ankle sprain, some people recover in four days, while others might require 13—it varies from person to person. Now imagine how complex the brain is, and it becomes apparent why recovery time from concussions can be even more individualized. Research is being done concerning possible direct treatments for concussions, but the majority of treatments involve treating the symptoms. Post-concussion syndrome symptoms can range from headaches and difficulty with cognitive functions such as concentration and memory (different from amnesia) to emotional and behavioral symptoms. These are usually addressed through a combination of medications, cognitive rest, physical therapy, behavioral therapy, and even very light exercise.

In order to return to the playing field following a concussion, a player must clear a succession of regimented hurdles while remaining symptom-free at every step along the way, to ensure that it’s safe to resume participation in practice and games. The process begins after the player has been symptom-free (including headaches) for a period of time, followed by light cardiovascular exercise, usually on a stationary bike. The next step involves a combination of very light weightlifting and jogging on a treadmill, which progresses to heavier weights, sprinting, and eventually baseball activities. This timeline, like the symptoms themselves, is highly individualized and must be monitored closely.

It's a good sign to see Morneau resuming baseball activities, even if he is not cleared for games yet. That will obviously be the final step, but at least he appears to be inching closer with each passing day. Any setbacks will cause a change in this timetable, but for now, he appears to be on track to return to the Twins’ lineup.

David Aardsma (Labrum surgery, left hip)

After continued discomfort in his lower left oblique and hip in the offseason, David Aardsma underwent surgery earlier this winter to repair the labral tear in his left hip. Healthy pitchers usually have a decreased range of motion (compared to their dominant hip) in the non-dominant hip. In the right-handed Aardsma's case, the left hip with the labral tear was his non-dominant one. This hip helped to provide the power during his delivery. When the hip rotation decreases from either bone-related or soft-tissue restrictions, ball velocity takes a hit as the pitcher compensates by throwing across his body.

There are a limited number of pitchers who have undergone surgeries on their non-dominant hip, but the Baseball Injury Tool database does include a few, including Jason Isringhausen in 2004 and Jason Vargas in 2008. Aardsma is expected back in approximately one month, but it’s tough to gauge just how effective he will be based on those comps: Isringhausen required a second hip surgery in 2006 and the strides he had made in improving his control seemed to vanish, while Vargas has been both healthy and effective since returning from his procedure. In the meantime, Brandon League (3.41 ERA, 7.2 K/9, 2.3 K/BB projected by PECOTA) will fill in for Aardsma as the team’s closer.

Jeff Keppinger (Sesamoid removal, left foot)

Sesamoiditis can be an extremely painful condition. It is an inflammatory condition of the sesamoid bones and the surrounding soft tissues near the base of the big toe. The sesamoid bones impact the ground with every step, and therefore the inflammation can be quite painful, but it rarely leads to surgery. Even though sesamoiditis can be caused from fractures to these bones, it is typically more closely related to impact and overuse activities, with a higher prevalence in ballet dancers and people with elevated arches. Clearly, Keppinger is not a ballet dancer (at least not during the regular season—the Astros’ lack of postseason play gives him plenty of time for extracurricular activities), but his foot type may lead to undo stresses to the area.

Sesamoiditis usually responds to a combination of physical therapy and activity and footwear modification, but rarely leads to surgery except in severe, chronic cases. There were reports of a stress reaction in the sesamoids, which is a pre-cursor to stress fracture, but the treatments remain the same. Keppinger's symptoms did not respond to these conservative treatments, which started last fall after he was placed on the disabled list in August. He subsequently underwent a relatively simple procedure in January, which involved removing the bone, debriding the affected area, and then suturing both the tendon and the skin.

Keppinger will likely be out for the first month of the season to allow the area to heal and retrain his foot to handle the newly distributed forces. Once he returns, there shouldn't be any concerns for re-injury. That’s good news for the Astros, who don’t have the infield depth to cover Keppinger’s absence for very long.

Rich Harden (Latissimus soreness)

Rich Harden has an injury history a mile long, and he is already in the news for unfortunate reasons this spring after experiencing soreness in his latissimus dorsi below the shoulder blade. He altered his mechanics after a strain of the gluteal muscle and shoulder soreness in 2010, but there is a very fine line to tread with such corrections. Harden is expected to miss at least a few weeks in order to keep this from progressing into something much worse that will keep him out even longer—for instance, in 2010, Jake Peavy had his latissimus dorsi muscle detach from the bone—and effectively flush Oakland’s $1.5 million down the drain. Having dealt Vin Mazzaro to the Royals and let Justin Duchscherer walk, the A’s don’t have as many options to spot start as they did in 2010, so the health of Harden is important to this club.

Omar Beltre (Spine surgery)

Beltre underwent surgery to repair a condition of the spinal cord called spinal stenosis. This is a narrowing of the spinal canal to the point that it compresses the cord itself. It can result from multiple causes, ranging from infection to herniated discs to congenital conditions, and can affect any level of the spine, though it is most often seen in the cervical and lumbar regions. We hear about spinal stenosis more often in football, where it can be a disqualifying condition due to its association with traumatic spinal cord injuries. In baseball, however, there doesn't appear to be any record for surgical intervention to correct the condition in an active player, so the return-to-play timeline is more of an estimate than empirically based. Beltre is expected to resume baseball activities in roughly six to eight weeks, but he will likely require another four to six weeks on top of that before being seen in any games.

Dana Eveland (Left Hamstring Strain)

Scott Olsen (Left Hamstring Strain)

The first week of camp often produces several strains, and this year is no different. After pulling up lame while running sprints this week, Eveland is expected to miss a few weeks with a mild-to-moderate left hamstring strain. Hamstring strain injuries come with a straightforward rehabilitation and recovery process, but they still have a propensity for re-injury for physiologic reasons. While Eveland’s recovery is expected to last a few weeks, Olsen is expected back in about one week after stopping workouts on Thursday. His rehabilitation should be quick, and he'll be ready to go in Grapefruit League games.

Flesh Wounds

Jeremy Sowers underwent the first season-ending surgery of the year to repair his left rotator cuff. He won’t be back for 9-12 months, which keeps the disappointing former first-round pick from reaching his former promise once again… The shoulder MRI on Jake Peavy came back clean, and he has been throwing well while recovering from his own latissimus injury… Brandon Webb reports “normal soreness” in his arm after throwing recently—we’ll have to see how it corresponds to his velocity and sinker movement to tell how he's really doing… Dustin Pedroia has been on the field taking part in drills without any limitations and appears to have recovered from surgery on his left foot… Adrian Gonzalez isn't quite ready for full participation in camp but is progressing well from surgery on his right shoulder… An MRI on Francisco Liriano came back clean. The southpaw’s sore left shoulder will be handled very carefully—no one on the Twins wants to lose the magic he recaptured in 2010, and the pitching staff can’t afford to take a hit like that… Derrek Lee is about 7-10 days away from taking batting practice following surgery on his right thumb in November… Chipper Jones, recovering from an ACL injury that ended his 2010 campaign, has been taking grounders and batting practice and recently starting running the bases at full speed. The Braves will likely take it slowly at first, but he should be ready for Opening Day… Eli Whiteside underwent an MRI on his elbow and was found to have only inflammation… Jim Edmonds announced his retirement on Thursday after a comeback attempt following Achilles surgery. Jay Jaffe, please start the Hall of Fame campaign good and early for Mr. Edmonds, so he gets the enshrinement he deserves.